kvm: emulating exchange as write
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BUG: KCSAN: data-race in install_new_memslots / mmio_info_in_cache

write to 0xffff88809ba31000 of 8 bytes by task 18214 on cpu 0:
 install_new_memslots+0xe9/0x130 arch/x86/kvm/../../../virt/kvm/kvm_main.c:1077
 kvm_set_memslot+0x800/0xb70 arch/x86/kvm/../../../virt/kvm/kvm_main.c:1153
 __kvm_set_memory_region+0x91c/0xc20 arch/x86/kvm/../../../virt/kvm/kvm_main.c:1300
 kvm_set_memory_region+0x31/0x50 arch/x86/kvm/../../../virt/kvm/kvm_main.c:1321
 kvm_vm_ioctl_set_memory_region arch/x86/kvm/../../../virt/kvm/kvm_main.c:1333 [inline]
 kvm_vm_ioctl+0x662/0x18b0 arch/x86/kvm/../../../virt/kvm/kvm_main.c:3604
 vfs_ioctl fs/ioctl.c:47 [inline]
 ksys_ioctl+0x101/0x150 fs/ioctl.c:763
 __do_sys_ioctl fs/ioctl.c:772 [inline]
 __se_sys_ioctl fs/ioctl.c:770 [inline]
 __x64_sys_ioctl+0x47/0x60 fs/ioctl.c:770
 do_syscall_64+0xc7/0x3b0 arch/x86/entry/common.c:295
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

read to 0xffff88809ba31000 of 8 bytes by task 18202 on cpu 1:
 vcpu_match_mmio_gen arch/x86/kvm/x86.h:183 [inline]
 vcpu_match_mmio_gpa arch/x86/kvm/x86.h:211 [inline]
 mmio_info_in_cache+0x131/0x1d0 arch/x86/kvm/mmu/mmu.c:3944
 kvm_mmu_page_fault+0x182/0xac0 arch/x86/kvm/mmu/mmu.c:5480
 handle_ept_violation+0x1ce/0x430 arch/x86/kvm/vmx/vmx.c:5196
 vmx_handle_exit+0x1de/0xfe0 arch/x86/kvm/vmx/vmx.c:5980
 vcpu_enter_guest+0xc00/0x3740 arch/x86/kvm/x86.c:8481
 vcpu_run arch/x86/kvm/x86.c:8544 [inline]
 kvm_arch_vcpu_ioctl_run+0x281/0xd60 arch/x86/kvm/x86.c:8766
 kvm_vcpu_ioctl+0x70b/0x9d0 arch/x86/kvm/../../../virt/kvm/kvm_main.c:3138
 vfs_ioctl fs/ioctl.c:47 [inline]
 ksys_ioctl+0x101/0x150 fs/ioctl.c:763
 __do_sys_ioctl fs/ioctl.c:772 [inline]
 __se_sys_ioctl fs/ioctl.c:770 [inline]
 __x64_sys_ioctl+0x47/0x60 fs/ioctl.c:770
 do_syscall_64+0xc7/0x3b0 arch/x86/entry/common.c:295
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 18202 Comm: syz-executor.3 Not tainted 5.7.0-rc1-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
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